Oscillating shuttle mechanism for sewing machines



Feb. 16, 1932. R. EAGLESHAM 1,345,788

OSCILLATING SHUTTLE MECHANISM FOR SEWING MACHINES Filed Feb.- 6, 1931 Jwuentoa:

12066115 Egles/za'm a Y. Lu

Patented Feb. 16, 1932 UNITED STATES PATENT OFFICE ROBERT EAGLESHAM, OF DENNISTOUN, GLASGOW, SCOTLAND, ASSIGNOR TO THE SINGER MANUFACTURING COMPANY, OF ELIZABETH, NEW

JERSEY JERSEY, A CORPORATION OF NEW OSCILLATING SHUTTLE MECHANISM FOR SEWING MACHINES Application flled February 6, 1931, Serial No. 513,924, and in Great Britain February 21, 1930.

This invention relates to oscillating shuttle mechanism for lock-stitch sewing machines particularly sewing machines fitted with a central bobbin, and has for an object to provide Gfl GCtlVQ means for cushioning the action of the shattle driver in imparting oscillation to the shuttle with a view to obtaining silence and smoothness of running. A further object of the invention is to provide a cushioned shuttle driver of sturdy and durablc construction.

According to the invention there is fitted to the inner or concave face of the shuttledriving head a leaf spring curved to approximately the contour of said face and fixed to the driving head by screws spaced from the tips of the horns of the shuttle-driving head so that the end-portions of the spring have a certain freedom. The central portion of the face of the shuttle-driving head is preferably more sharply curved than the end-portions, and the central portion of the leaf-spring which is fixed to said face is preferably more sharply curved than the end-portions of the spring which stand slightly spaced from the adjacent faceportions of the shuttle-driving head. Preferably, the central portion of the face of the shuttle-driving head is concentric with the shuttle-driving shaft 14. The end-portions or horns, however, preferably curve outwardly from the circular arc of the central portion.

The spring overlaps the tips of the horns of the shuttle-driving head at both ends, one end of the spring being preferably out-turned at a short distance from the adjacent horn tip and the other end of the spring being preferably curled round the other horn tip. Thus, the tip ends of the spring beyond the fastening screws are engaged by the shuttle and the forces applied to the tips of the spring are applied at angles to the respective faceportions of the spring, whereby the face-portions may absorb said forces by uniform bending actions between their tip ends and the centrally fastened portion. Thus a sturdy leaf-spring may be used while still retaining the necessary resiliency.

Oscillating shuttle mechanism constructed in accordance with the invention is illustrated in the accompanying drawings in which Figs. 1 and 2 are elevations at right angles to each other and Fig. 3 isa perspective view of the shuttle-driving head.

Referring to the drawings, 1 denotes the oscillatory shuttle-driving head and 2 denotes the shuttle to which oscillatory movements are imparted by the head 1.

As shown, and in accordance with the invention, there is fitted to the inner or con-- cave face 3 of the shuttle-driving head 1 a leaf-spring 4 curved to approximately the contour of said face 3 and fixed to the head by screws 5, 6 spaced from the tips of the horns 7, 8, respectively, of the shuttle-driv ing head 1 so that the wing-portions 4: 4 of the spring 1 have a certain freedom. The central portion 4 of the spring is curved concentric to the axis of the shaft 14 and is more sharply curved than the wing-portions 4: and 4 The end 9 of the spring 4 is out-turned at a short distance from the tip of the horn 7 and the other end 10 of the spring is curled round the tip of the born 8, the ends 9, 10 forming cushioningmembers interposed between the driving head 1 and the impact faces 11, 12, respectively, of the shuttle 2.

14 denotes the usual oscillatory shuttle-. driving shaft. In the operation of the machine the tips of the spring wings 4: and 4 are subjected alternately to forces f, 7, directed tangentially to the arcs of motion of the contacting portions of the shuttle. The forces f, 7 stand at angles to the respective faces of the wing-portions 4 and 4 of the leaf-spring which wing-portions are therefore subjected to uniform bending actions from the fastening screws 5 to their tip ends.

It will be evident that the spring 4, in ad dit-ion to providing an efficient cushion between the shuttle-driving head 1 and the shuttle 2, will also afford free passage for the needle-thread when the shuttle is in cast-off position, the leaf action of the spring being so adjusted that a nominal thread clearance of say .010" is afforded between the spring and the heel of the shuttle and so that there exists between the under side of the wingportions 4 4 of the spring and the horns t, 8, a clearance which amounts to approximately .012 but which may vary according to the shape and thickness of thespring. Except for the contacts of the tip ends of the spring with the shuttle, the latter is entirely clear of engagement with the spring and free passage for the needle-thread loops is thereby insured.

Should the shuttle-driver meet with resistance liable to damage the spring, the spring will yield at either end until it is backed up by the rigid shuttle-driving head, and is not stressed beyond its elastic. limit.

The spring is readily replaceable or exchangeable by unscrewing the screws 5, 6.

Having thus set forth the nature of the invention, what I claim herein is 1. In oscillating shuttle mechanism for lock-stitch sewing machines the provision, for

the purpose specified, on the inner or'concave 7 face of the shuttle-driving head of a leafspring curved to approximately the contour of said face, said spring extending over the tips of the horns of the shuttle-driving head and being fixed to the driving-head by means spaced from the tips of the horns whereby the end-portions of the spring are given a certain freedom, substantially as descrlbed. I

2-. In a sewing mach1ne,a reciprocating needle, a circular shuttle-race, a shuttle journaled in and entirely supported in operativeposition by said shuttle-race, an oscillatoryshuttle-driving shaft, a shuttle-driving head fixed to said shaft, said head having a pair of oppositely extending horns'and a concave face between the tips of said horns, said face facing the axis of oscillation of said shaft and being more sharply curved along its central portion than along its end-portions, and a leaf-spring curved to approximately the contour of said face, said spring extending over the tips of said horns and being fixed to the more sharply curved central portion of the face of the shuttle-driving head, the more broadly curved portions of the spring adjacent the more sharply curved central portion standing slightly spaced from the adjacent face-portions of the shuttledriving head, said spring engaging the shuttle only at its tip ends adjacent the tips of said horns and otherwise being entirely clear of the shuttle for the free passage of the needle-thread loops.

In testimony whereof I have signed my name to this specification.

I ROBERT EAGLESHAM. 

